[1.20.2] Support common registration packets. Add configuration task API

build.gradle

@@ -223,6 +223,7 @@ allprojects {
 
 		testImplementation "net.fabricmc:fabric-loader-junit:${project.loader_version}"
 		testImplementation sourceSets.testmodClient.output
+		testImplementation 'org.mockito:mockito-core:5.4.0'
 	}
 
 	test {

fabric-networking-api-v1/src/client/java/net/fabricmc/fabric/api/client/networking/v1/ClientConfigurationNetworking.java

@@ -31,7 +31,6 @@
 import net.minecraft.util.thread.ThreadExecutor;
 
 import net.fabricmc.fabric.api.networking.v1.FabricPacket;
-import net.fabricmc.fabric.api.networking.v1.PacketByteBufs;
 import net.fabricmc.fabric.api.networking.v1.PacketSender;
 import net.fabricmc.fabric.api.networking.v1.PacketType;
 import net.fabricmc.fabric.api.networking.v1.ServerConfigurationNetworking;
@@ -384,9 +383,14 @@ public static <T extends FabricPacket> void send(T packet) {
 		Objects.requireNonNull(packet, "Packet cannot be null");
 		Objects.requireNonNull(packet.getType(), "Packet#getType cannot return null");
 
-		PacketByteBuf buf = PacketByteBufs.create();
-		packet.write(buf);
-		send(packet.getType().getId(), buf);
+		final ClientConfigurationNetworkAddon addon = ClientNetworkingImpl.getClientConfigurationAddon();
+
+		if (addon != null) {
+			addon.sendPacket(packet);
+			return;
+		}
+
+		throw new IllegalStateException("Cannot send packet while not configuring!");
 	}
 
 	private ClientConfigurationNetworking() {

fabric-networking-api-v1/src/client/java/net/fabricmc/fabric/api/client/networking/v1/ClientPlayNetworking.java

@@ -31,7 +31,6 @@
 import net.minecraft.util.thread.ThreadExecutor;
 
 import net.fabricmc.fabric.api.networking.v1.FabricPacket;
-import net.fabricmc.fabric.api.networking.v1.PacketByteBufs;
 import net.fabricmc.fabric.api.networking.v1.PacketSender;
 import net.fabricmc.fabric.api.networking.v1.PacketType;
 import net.fabricmc.fabric.api.networking.v1.ServerPlayNetworking;
@@ -339,6 +338,16 @@ public static Packet<ServerCommonPacketListener> createC2SPacket(Identifier chan
 		return ClientNetworkingImpl.createC2SPacket(channelName, buf);
 	}
 
+	/**
+	 * Creates a packet which may be sent to the connected server.
+	 *
+	 * @param packet the fabric packet
+	 * @return a new packet
+	 */
+	public static <T extends FabricPacket> Packet<ServerCommonPacketListener> createC2SPacket(T packet) {
+		return ClientNetworkingImpl.createC2SPacket(packet);
+	}
+
 	/**
 	 * Gets the packet sender which sends packets to the connected server.
 	 *
@@ -381,9 +390,13 @@ public static <T extends FabricPacket> void send(T packet) {
 		Objects.requireNonNull(packet, "Packet cannot be null");
 		Objects.requireNonNull(packet.getType(), "Packet#getType cannot return null");
 
-		PacketByteBuf buf = PacketByteBufs.create();
-		packet.write(buf);
-		send(packet.getType().getId(), buf);
+		// You cant send without a client player, so this is fine
+		if (MinecraftClient.getInstance().getNetworkHandler() != null) {
+			MinecraftClient.getInstance().getNetworkHandler().sendPacket(createC2SPacket(packet));
+			return;
+		}
+
+		throw new IllegalStateException("Cannot send packets when not in game!");
 	}
 
 	private ClientPlayNetworking() {

fabric-networking-api-v1/src/client/java/net/fabricmc/fabric/impl/networking/client/ClientConfigurationNetworkAddon.java

@@ -31,12 +31,14 @@
 import net.fabricmc.fabric.api.client.networking.v1.ClientConfigurationConnectionEvents;
 import net.fabricmc.fabric.api.client.networking.v1.ClientConfigurationNetworking;
 import net.fabricmc.fabric.api.client.networking.v1.ClientPlayNetworking;
+import net.fabricmc.fabric.api.networking.v1.FabricPacket;
 import net.fabricmc.fabric.impl.networking.AbstractChanneledNetworkAddon;
 import net.fabricmc.fabric.impl.networking.ChannelInfoHolder;
 import net.fabricmc.fabric.impl.networking.NetworkingImpl;
 import net.fabricmc.fabric.impl.networking.payload.PacketByteBufPayload;
 import net.fabricmc.fabric.mixin.networking.client.accessor.ClientCommonNetworkHandlerAccessor;
 import net.fabricmc.fabric.mixin.networking.client.accessor.ClientConfigurationNetworkHandlerAccessor;
+import net.fabricmc.fabric.mixin.networking.client.accessor.ClientLoginNetworkHandlerAccessor;
 
 public final class ClientConfigurationNetworkAddon extends AbstractChanneledNetworkAddon<ClientConfigurationNetworking.ConfigurationChannelHandler> {
 	private final ClientConfigurationNetworkHandler handler;
@@ -65,8 +67,17 @@ public void lateInit() {
 	}
 
 	public void onServerReady() {
-		this.sendInitialChannelRegistrationPacket();
-		this.sentInitialRegisterPacket = true;
+		// Do nothing for now
+	}
+
+	@Override
+	protected void receiveRegistration(boolean register, PacketByteBuf buf) {
+		super.receiveRegistration(register, buf);
+
+		if (register && !this.sentInitialRegisterPacket) {
+			this.sendInitialChannelRegistrationPacket();
+			this.sentInitialRegisterPacket = true;
+		}
 	}
 
 	/**
@@ -100,6 +111,11 @@ public Packet<?> createPacket(Identifier channelName, PacketByteBuf buf) {
 		return ClientPlayNetworking.createC2SPacket(channelName, buf);
 	}
 
+	@Override
+	public Packet<?> createPacket(FabricPacket packet) {
+		return ClientPlayNetworking.createC2SPacket(packet);
+	}
+
 	@Override
 	protected void invokeRegisterEvent(List<Identifier> ids) {
 		C2SPlayChannelEvents.REGISTER_CONFIGURATION.invoker().onChannelRegister(this.handler, this, this.client, ids);
@@ -147,6 +163,10 @@ protected void invokeDisconnectEvent() {
 
 	@Override
 	protected boolean isReservedChannel(Identifier channelName) {
-		return NetworkingImpl.isReservedPlayChannel(channelName);
+		return NetworkingImpl.isReservedCommonChannel(channelName);
+	}
+
+	public ChannelInfoHolder getChannelInfoHolder() {
+		return (ChannelInfoHolder) ((ClientLoginNetworkHandlerAccessor) handler).getConnection();
 	}
 }

fabric-networking-api-v1/src/client/java/net/fabricmc/fabric/impl/networking/client/ClientNetworkingImpl.java

@@ -16,15 +16,13 @@
 
 package net.fabricmc.fabric.impl.networking.client;
 
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.List;
-import java.util.concurrent.CompletableFuture;
+import java.util.Objects;
 
 import org.jetbrains.annotations.Nullable;
 
 import net.minecraft.client.MinecraftClient;
 import net.minecraft.client.gui.screen.ConnectScreen;
+import net.minecraft.client.network.ClientConfigurationNetworkHandler;
 import net.minecraft.client.network.ClientLoginNetworkHandler;
 import net.minecraft.client.network.ClientPlayNetworkHandler;
 import net.minecraft.network.ClientConnection;
@@ -40,27 +38,35 @@
 import net.fabricmc.fabric.api.client.networking.v1.ClientLoginNetworking;
 import net.fabricmc.fabric.api.client.networking.v1.ClientPlayConnectionEvents;
 import net.fabricmc.fabric.api.client.networking.v1.ClientPlayNetworking;
+import net.fabricmc.fabric.api.networking.v1.FabricPacket;
 import net.fabricmc.fabric.api.networking.v1.PacketByteBufs;
-import net.fabricmc.fabric.impl.networking.ChannelInfoHolder;
+import net.fabricmc.fabric.api.networking.v1.PacketSender;
+import net.fabricmc.fabric.impl.networking.CommonPacketsImpl;
+import net.fabricmc.fabric.impl.networking.CommonRegisterPayload;
+import net.fabricmc.fabric.impl.networking.CommonVersionPayload;
 import net.fabricmc.fabric.impl.networking.GlobalReceiverRegistry;
 import net.fabricmc.fabric.impl.networking.NetworkHandlerExtensions;
 import net.fabricmc.fabric.impl.networking.NetworkingImpl;
+import net.fabricmc.fabric.impl.networking.payload.FabricPacketPayload;
 import net.fabricmc.fabric.impl.networking.payload.PacketByteBufPayload;
-import net.fabricmc.fabric.mixin.networking.client.accessor.ClientLoginNetworkHandlerAccessor;
 import net.fabricmc.fabric.mixin.networking.client.accessor.ConnectScreenAccessor;
 import net.fabricmc.fabric.mixin.networking.client.accessor.MinecraftClientAccessor;
 
 public final class ClientNetworkingImpl {
-	public static final GlobalReceiverRegistry<ClientLoginNetworking.LoginQueryRequestHandler> LOGIN = new GlobalReceiverRegistry<>();
-	public static final GlobalReceiverRegistry<ClientConfigurationNetworking.ConfigurationChannelHandler> CONFIGURATION = new GlobalReceiverRegistry<>();
-	public static final GlobalReceiverRegistry<ClientPlayNetworking.PlayChannelHandler> PLAY = new GlobalReceiverRegistry<>();
+	public static final GlobalReceiverRegistry<ClientLoginNetworking.LoginQueryRequestHandler> LOGIN = new GlobalReceiverRegistry<>(NetworkState.LOGIN);
+	public static final GlobalReceiverRegistry<ClientConfigurationNetworking.ConfigurationChannelHandler> CONFIGURATION = new GlobalReceiverRegistry<>(NetworkState.CONFIGURATION);
+	public static final GlobalReceiverRegistry<ClientPlayNetworking.PlayChannelHandler> PLAY = new GlobalReceiverRegistry<>(NetworkState.PLAY);
 	private static ClientPlayNetworkAddon currentPlayAddon;
 	private static ClientConfigurationNetworkAddon currentConfigurationAddon;
 
 	public static ClientPlayNetworkAddon getAddon(ClientPlayNetworkHandler handler) {
 		return (ClientPlayNetworkAddon) ((NetworkHandlerExtensions) handler).getAddon();
 	}
 
+	public static ClientConfigurationNetworkAddon getAddon(ClientConfigurationNetworkHandler handler) {
+		return (ClientConfigurationNetworkAddon) ((NetworkHandlerExtensions) handler).getAddon();
+	}
+
 	public static ClientLoginNetworkAddon getAddon(ClientLoginNetworkHandler handler) {
 		return (ClientLoginNetworkAddon) ((NetworkHandlerExtensions) handler).getAddon();
 	}
@@ -69,6 +75,19 @@ public static Packet<ServerCommonPacketListener> createC2SPacket(Identifier chan
 		return new CustomPayloadC2SPacket(new PacketByteBufPayload(channelName, buf));
 	}
 
+	public static Packet<ServerCommonPacketListener> createC2SPacket(FabricPacket packet) {
+		Objects.requireNonNull(packet, "Packet cannot be null");
+		Objects.requireNonNull(packet.getType(), "Packet#getType cannot return null");
+
+		if (NetworkingImpl.WRITE_FABRIC_PACKET_CALLING_THREAD) {
+			PacketByteBuf buf = PacketByteBufs.create();
+			packet.write(buf);
+			return createC2SPacket(packet.getType().getId(), buf);
+		}
+
+		return new CustomPayloadC2SPacket(new FabricPacketPayload(packet));
+	}
+
 	/**
 	 * Due to the way logging into a integrated or remote dedicated server will differ, we need to obtain the login client connection differently.
 	 */
@@ -134,29 +153,44 @@ public static void clientInit() {
 			currentConfigurationAddon = null;
 		});
 
-		// Register a login query handler for early channel registration.
-		ClientLoginNetworking.registerGlobalReceiver(NetworkingImpl.EARLY_REGISTRATION_CHANNEL, (client, handler, buf, listenerAdder) -> {
-			int n = buf.readVarInt();
-			List<Identifier> ids = new ArrayList<>(n);
+		// Version packet
+		ClientConfigurationNetworking.registerGlobalReceiver(CommonVersionPayload.PACKET_ID, (client, handler, buf, responseSender) -> {
+			var payload = new CommonVersionPayload(buf);
+			int negotiatedVersion = handleVersionPacket(payload, responseSender);
+			ClientNetworkingImpl.getAddon(handler).onCommonVersionPacket(negotiatedVersion);
+		});
 
-			for (int i = 0; i < n; i++) {
-				ids.add(buf.readIdentifier());
+		// Register packet
+		ClientConfigurationNetworking.registerGlobalReceiver(CommonRegisterPayload.PACKET_ID, (client, handler, buf, responseSender) -> {
+			var payload = new CommonRegisterPayload(buf);
+			ClientConfigurationNetworkAddon addon = ClientNetworkingImpl.getAddon(handler);
+
+			if (CommonRegisterPayload.PLAY_PHASE.equals(payload.phase())) {
+				if (payload.version() != addon.getNegotiatedVersion()) {
+					throw new IllegalStateException("Negotiated common packet version: %d but received packet with version: %d".formatted(addon.getNegotiatedVersion(), payload.version()));
+				}
+
+				addon.getChannelInfoHolder().getPendingChannelsNames(NetworkState.PLAY).addAll(payload.channels());
+				NetworkingImpl.LOGGER.debug("Received accepted channels from the server");
+				responseSender.sendPacket(new CommonRegisterPayload(addon.getNegotiatedVersion(), CommonRegisterPayload.PLAY_PHASE, ClientPlayNetworking.getGlobalReceivers()));
+			} else {
+				addon.onCommonRegisterPacket(payload);
+				responseSender.sendPacket(addon.createRegisterPayload());
 			}
+		});
+	}
 
-			ClientConnection connection = ((ClientLoginNetworkHandlerAccessor) handler).getConnection();
-			((ChannelInfoHolder) connection).getPendingChannelsNames(NetworkState.PLAY).addAll(ids);
-			NetworkingImpl.LOGGER.debug("Received accepted channels from the server");
-
-			PacketByteBuf response = PacketByteBufs.create();
-			Collection<Identifier> channels = ClientPlayNetworking.getGlobalReceivers();
-			response.writeVarInt(channels.size());
+	// Disconnect if there are no commonly supported versions.
+	// Client responds with the intersection of supported versions.
+	// Return the highest supported version
+	private static int handleVersionPacket(CommonVersionPayload payload, PacketSender packetSender) {
+		int[] commonlySupportedVersion = CommonPacketsImpl.intersection(payload.versions(), CommonPacketsImpl.SUPPORTED_COMMON_PACKET_VERSIONS);
 
-			for (Identifier id : channels) {
-				response.writeIdentifier(id);
-			}
+		if (commonlySupportedVersion.length == 0) {
+			throw new UnsupportedOperationException("Client does not support any requested versions from server");
+		}
 
-			NetworkingImpl.LOGGER.debug("Sent accepted channels to the server");
-			return CompletableFuture.completedFuture(response);
-		});
+		packetSender.sendPacket(new CommonVersionPayload(commonlySupportedVersion));
+		return CommonPacketsImpl.largest(commonlySupportedVersion);
 	}
 }

fabric-networking-api-v1/src/client/java/net/fabricmc/fabric/impl/networking/client/ClientPlayNetworkAddon.java

@@ -33,6 +33,7 @@
 import net.fabricmc.fabric.api.client.networking.v1.C2SPlayChannelEvents;
 import net.fabricmc.fabric.api.client.networking.v1.ClientPlayConnectionEvents;
 import net.fabricmc.fabric.api.client.networking.v1.ClientPlayNetworking;
+import net.fabricmc.fabric.api.networking.v1.FabricPacket;
 import net.fabricmc.fabric.impl.networking.AbstractChanneledNetworkAddon;
 import net.fabricmc.fabric.impl.networking.ChannelInfoHolder;
 import net.fabricmc.fabric.impl.networking.NetworkingImpl;
@@ -109,6 +110,11 @@ public Packet<?> createPacket(Identifier channelName, PacketByteBuf buf) {
 		return ClientPlayNetworking.createC2SPacket(channelName, buf);
 	}
 
+	@Override
+	public Packet<?> createPacket(FabricPacket packet) {
+		return ClientPlayNetworking.createC2SPacket(packet);
+	}
+
 	@Override
 	protected void invokeRegisterEvent(List<Identifier> ids) {
 		C2SPlayChannelEvents.REGISTER.invoker().onChannelRegister(this.handler, this, this.client, ids);
@@ -151,6 +157,6 @@ protected void invokeDisconnectEvent() {
 
 	@Override
 	protected boolean isReservedChannel(Identifier channelName) {
-		return NetworkingImpl.isReservedPlayChannel(channelName);
+		return NetworkingImpl.isReservedCommonChannel(channelName);
 	}
 }

fabric-networking-api-v1/src/main/java/net/fabricmc/fabric/api/networking/v1/FabricPacket.java

@@ -57,7 +57,7 @@
  *
  * @see ServerPlayNetworking#registerGlobalReceiver(PacketType, ServerPlayNetworking.PlayPacketHandler)
  * @see ServerPlayNetworking#send(ServerPlayerEntity, PacketType, FabricPacket)
- * @see PacketSender#sendPacket(PacketType, FabricPacket)
+ * @see PacketSender#sendPacket(FabricPacket)
  */
 public interface FabricPacket {
 	/**

fabric-networking-api-v1/src/main/java/net/fabricmc/fabric/api/networking/v1/FabricServerConfigurationNetworkHandler.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.fabricmc.fabric.api.networking.v1;
+
+import net.minecraft.server.network.ServerConfigurationNetworkHandler;
+import net.minecraft.server.network.ServerPlayerConfigurationTask;
+import net.minecraft.util.Identifier;
+
+/**
+ * Fabric-provided extensions for {@link ServerConfigurationNetworkHandler}.
+ * This interface is automatically implemented via Mixin and interface injection.
+ */
+public interface FabricServerConfigurationNetworkHandler {
+	/**
+	 * Enqueue a {@link ServerPlayerConfigurationTask} task to be processed.
+	 *
+	 * <p>Before adding a task use {@link ServerConfigurationNetworking#canSend(ServerConfigurationNetworkHandler, Identifier)}
+	 * to ensure that the client can process this task.
+	 *
+	 * <p>Once the client has handled the task a packet should be sent to the server.
+	 * Upon receiving this packet the server should call {@link FabricServerConfigurationNetworkHandler#completeTask(ServerPlayerConfigurationTask.Key)}
+	 *
+	 * @param task the task
+	 */
+	default void addTask(ServerPlayerConfigurationTask task) {
+		throw new UnsupportedOperationException("Implemented via mixin");
+	}
+
+	/**
+	 *
+	 * @param key the key
+	 */
+	default void completeTask(ServerPlayerConfigurationTask.Key key) {
+		throw new UnsupportedOperationException("Implemented via mixin");
+	}
+}